In the study supported by the Fogarty grant from 1994 to 1996, we developed a model for mechanisms of cytoskeletal control of focal adhesions [FA] in cultured fibroblasts. According to this model, development of FA has two stages, initiation and maturation, and each stage is controlled by different microtubule-dependent reorganizations of the actin cortex. The aim of this project is to find out whether this mechanism controls FA not only in the polarized fibroblasts but also in the cells of another main tissue type, non-polarized epitheliocytes with profoundly different organization of the cytoskeleton and FA. Our hypothesis is that similar basic mechanisms lead to development of very different systems in these two cell types due to the differences of microtubular systems. Dynamics of FA and of the cytoskeleton will be assessed by immunochemical and immuno- histochemical methods and by interference-reflection microscopy; cortical tensions will be assessed by the methods developed in the laboratory of the US PI. Rho-dependent contractility will be modulated by a series of activators and inhibitors. To alter the microtubular system, we will use specific drugs and injections of antibodies against the microtubular motor protein, kinesin.